Arkham City, like its predecessor, Arkham Asylum, is an open world action video game that incorporates elements of stealth and predator tactics. All of the gadgets previously obtained in the first game will be present at the start of Arkham City, most of them will be possessing improved or new capabilities; for example, the Cryptographic sequencer can also track signals. An additional gadget have been revealed: smoke bombs to confuse enemies. The game incorporates more puzzle elements; the use of Batman's "Detective Mode", which highlights elements such as enemy skeletons and clues on-screen, is used to perform forensic activities such as tracing the origin of a sniper round. The player also has access to a criminal database that tracks the major villains across the city and the forensic puzzles much like the first game. However, Rocksteady's art director David Hego stated that the use of Detective Mode will be changed to an "augmented reality mode", as they found players had completed Arkham Asylum using Detective Mode all of the time. Optional challenges from the Riddler to collect hidden trophies placed around the city will also be present, but it will require additional effort to locate these, such as interrogation of men loyal to the Riddler.
Official Batman: Arkham City Trailer
The player controls Batman, making his way around Arkham City to complete mission objectives. In addition to the primary mission, the game introduces secondary missions featuring a number of key characters and their stories. The player can opt to move silently, avoiding inmates and other enemies using a combination of gadgets and to sneak up on enemies to take them down silently, using new tactics to surprise the enemy. At other times, Batman may be forced to fight through inmates using an improved version of the combat system from Arkham Asylum, allowing for multiple simultaneous counters, reactions to thrown objects, and the use of all of Batman's gadgets within combat. Movement about the city is made difficult due to the formation of gangs and territory between rival villains, such as Two-Face and the Joker, that causes in-fighting that Batman needs to avoid.
Catwoman is also a playable character with her own heist-focused storyline at specific points in the game. Her combat is more acrobatics-oriented and features her claws, whip, and bolas. She has her own version of Detective Mode to locate items to steal.